Cavalex DCC (not sound) Bachmann Back EMF?!?

[Melly]

I've only recently put my layout back together and decided I needed to 'run in' my Cavalex Class 56.  These are the DCC ready versions and I'm awaiting for the ESU 5629 (configured?) chips to become available again.  So I popped in some spare Bachmann 36-557 21 pin.  Now, the loco ran fantastically in analogue, but in DCC it was very 'jerky'.  After some trouble shooting, I turned off the Back EMF on the Chip.  Now I have smooth running but the loco wont move until speed step 24 and if rest a finger on the engine it stops; the wheels don't even turn.  Loco slows through point work. So clearly a compatibility / configuration issue.  

 

Hopefully, those of you with infinitely more knowledge than me will be able to point me in the right direction to improve the situation until the USU Chips are available.

 

Many thanks.

[Kaput]

Which version of the 36-557 is it? (most obvious difference is really whether its green or blue).

[Ron Ron Ron]

9 hours ago, Kaput said:

Which version of the 36-557 is it? (most obvious difference is really whether its green or blue).

If Kaput doesn’t mind me adding a note to this, to flesh out the issue of green and blue……

 

For some unfathomable and stupid reason, Bachmann sold 2 completely different decoders under the same catalogue number (36-557).

The (problematic) green one was from SoundTraxx and the blue one was from one of their usual suppliers, ESU.

There was nothing in common between these two products, other them both being DCC decoders and having the same type of connector pin interface.

 

.

[Kaput]

It gets better, the ESU version of the 36-557 is a Lokpilot Standard 1.0 so fairly basic in ESU terms but the latest 36-557A (yup, they stuck an A on the end this time) is a full fat Lokpilot 5

[Ron Ron Ron]

4 hours ago, Kaput said:

It gets better....

......the latest 36-557A (yup, they stuck an A on the end this time) is a full fat Lokpilot 5

 

It's a remarkable turn around from historically offering decent, known brand, budget decoders under the Bachmann banner, to now offering the likes of the LokPilot 5 DCC** and quality Zimo decoders, as Bachmann catalogue items.;

....but why use the same catalogue no. with a suffix, rather than a new number?

It's not as if there's shortage of cat. numbers in that series.

 

Incidentally, Bachmann still offer the LokPilot Standard 1.0 's successor, the LokPilot 5 Basic, in 8-pin form, as model no. 36-566A (a.k.a. ESU no. 59020 )

 

 

**  LokPilot 5 DCC   (ESU no. 59629)  = Bachmann 36-557A

 

 

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[Melly]

Hi all.  Many thanks for your detailed response.  Really helps.

 

Regards M

[Melly]

On 23/07/2024 at 09:30, Ron Ron Ron said:

If Kaput doesn’t mind me adding a note to this, to flesh out the issue of green and blue……

 

For some unfathomable and stupid reason, Bachmann sold 2 completely different decoders under the same catalogue number (36-557).

The (problematic) green one was from SoundTraxx and the blue one was from one of their usual suppliers, ESU.

There was nothing in common between these two products, other them both being DCC decoders and having the same type of connector pin interface.

 

.

Hi Ron Ron Ron, sadly (for me) its the Blue 36-557 that created the jerky running.  Identical on 2 locos both with the same 36-557 decoders.  

[Kaput]

31 minutes ago, Melly said:

Hi Ron Ron Ron, sadly (for me) its the Blue 36-557 that created the jerky running.  Identical on 2 locos both with the same 36-557 decoders.  

 

Blue ones are ESU at least. Have you tried autotune? (Can't remember if ye olde LP Standard has it but worth a try)

Set CV54 to 0 then press F1 on your controller. Make sure there is plenty of space in front of the loco.

[RFS]

1 hour ago, Melly said:

Hi all.  Many thanks for your detailed response.  Really helps.

 

Regards M

 

Have you tried setting up the Back EMF CVs?  Detailed article here on the South West Digital website. With early Bachmann decoders it's CVs 54 and 55 you need to adjust. 

[Melly]

19 hours ago, RFS said:

 

Have you tried setting up the Back EMF CVs?  Detailed article here on the South West Digital website. With early Bachmann decoders it's CVs 54 and 55 you need to adjust. 

Hi RFS, I've now got a single version of the ESU 5629 and all is well.  I had completely disabled the back EMF on the Bachmann Chip CV49 from 17 to zero. But thanks for the link - that's really useful.